I have probably never masturbated for 2 hours. I imagine that at that point it would stop giving pleasure and start causing pain instead... so that seems a bit undesirable? Of course some people may like feeling pain...

What do you feel is more complex than it needs to be?

In some animes/ manga I watched or read characters were playing a game called Mahjong. I never understood that game. It seemed so complex that I just gave up on understanding it.